Sir: We appreciate the interest Dr. Smith has taken in our work which examined venlafaxine in adults with attention- deficit/hyperactivity disorder (ADHD). However, our rationale for initiating a clinical trial with venlafaxine in adults with this syndrome was not simply due to the fact that venlafaxine is an antidepressant. The reason we initiated a trial with venlafaxine was that the effect of venlafaxine on both serotonergic and noradrenergic neural transmission is a pharmacologic profile shared with the tricyclic antidepressants.